LOL. Looks like it's really hard to understand why Poland joined the EU. Theoretically speaking, Poland gets more money from the EU than she pays to the common kitty. In fact, the criteria of getting money for perticular projects from the EU are so complicated that Poland is in the red.
The real argument for the EU is access to the common market. Within the common legal framework you have "complete no kidding free trade" and that's why e.g. Dell serves the German market with factories in Poland, 70% of all trade is with EU countries as well as the majority of all foreign investment in Poland. There are even common company statutes (SE = Societas Europaea, e.g. the former Porsche SE).
The Secret of World Peace